Should I ignore the occasional Invalid viewstate error?

Question

Every now and then (once every day or so) we\'re seeing the following types of errors in our logs for an ASP.NET 3.5 application

• Invalid viewstate
• Inv

Answer 1

I had this kind of exception being thrown in my logs and had a very different cause from the others listed here. I did have a very large ViewState, which is part of the problem. But that was combining with another issue to cause these exceptions (and possibly occasional bad responses from IIS).

The code base I'm working on has some fancy code to avoid double clicks, and as part of that it adds some stuff to the javascript of every button's click event that disables the button after the first click, and then does the usual postback. But calling the postback like that was a problem because some of my buttons already had a postback call generated by .NET automatically. So I was ending up with double postbacks, one of which had an invalid ViewState. Removing the extra postback stopped the exceptions for me.

I know I should really be drastically decreasing the size of the ViewState, but this is a large legacy code base and a change like that would be very invasive.